<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div id="app">
        <span>
            {{message}}
        </span>
        <br>
        <button type="button" v-on:click="add">加10</button>
    </div>
    <script src="https://unpkg.com/vue@next"></script>
    <script>

        const vue = {
            data() {
                return {
                    message:0
                } 
            },
            methods: {
                add() {
                    this.message += 10
                }
            }
        }
        Vue.createApp(vue).mount("#app")

    </script>
    
</body>
</html>